1. Field of the Invention
The present invention relates to a computer system and more particularly to a an adjustable user input device for controlling cursor movement in a computer system.
2. Description of the Related Art
Computer systems in general and International Business Machines (IBM) compatible personal computer systems in particular have attained widespread use for providing computer power to many segments of today's modern society. A personal computer system can usually be defined as a desk top, floor standing, or portable computer that includes a system unit having a system processor and associated volatile and non-volatile memory, a display monitor, a keyboard, one or more diskette drives, a fixed disk storage device and an optional printer. One of the distinguishing characteristics of these systems is the use of a system board or mother board to electrically connect these components together. These personal computer systems are information handling systems which are designed primarily to give independent computing power to a single user and are inexpensively priced for purchase by individuals or small businesses. A personal computer system may also include one or a plurality of I/O devices (i.e. peripheral devices) which are coupled to the system processor and which perform specialized functions. Examples of I/O devices include modems, sound and video devices or specialized communication devices.
These personal computer systems are information handling systems which are designed primarily to give independent computing power to a single user or group of users and are inexpensively priced for purchase by consumers such as by individuals or small businesses.
Portable, battery-powered portable computers have become increasingly popular over the last several years due to their light weight and small size that permit them to be easily hand-carried in an ordinary briefcase and used by business travelers in cramped spaces, such as on airline seat back trays, lacking electrical plug-in facilities. Portable computers are often referred to as laptop, notebook, or subnotebook computers. These computers typically incorporate a flat panel display such as a liquid crystal display (LCD) or other relatively small display in the lid portion. The portable computer also incorporates both a hard and floppy disc drives, and a keyboard built into its main body portion. It is a fully self-contained computer system able to be conveniently used, for at least short periods of time, in situations and locations in which the use of a much larger desktop computer is not feasible.
The increase in the popularity of computer systems has been fueled by the improvement in the input devices used to facilitate the human interaction with these computer systems. In the past, the primary input device simply consisted of a keyboard. The human operator entered data by typing on alpha-numeric, special function, and arrow keys from the keyboard. The entered data was usually displayed on a display monitor.
Subsequently, a more sophisticated and user-friendly interface encompassing the use of a cursor to perform editing and selection functions was developed. Typically, an input device coupled to the computer system is manipulated by the user to control the movement of a cursor on the display monitor. One or more buttons are used to perform the desired selection functions. For example, a user can place a cursor over an icon displayed on the display monitor. Thereupon the icon can be selected by clicking the button. This "point-and-click" feature has proven to be extremely popular and has gained wide acceptance.
There are several different types of input devices for controlling the cursor that are commercially available today. Some of these types include a mouse, a trackball, a joystick, a writing pen, a stylus tablet, to name a few.
The latest cursor controlling device for a computer system is the touchpad or trackpad. One type of touchpad uses field-distortion or capacitive sensing technology.
Two layers of electrodes are arranged in a grid on the pad's flat planar surface to create an electrical field. Finger movement on the touchpad distorts the electrical field allowing the cursor movement to be controlled by the touch of a finger. A user moves the cursor or arrow on their computer display monitor by gliding their finger across the touchpad. To select items or launch applications, the user lightly taps the touch pad surface once or twice.
Touchpads require less space to operate than a mouse, therefore, they are more suitable for portable computers than a mouse. Touchpads are superior to trackballs in that they contain no moving parts and they do not get clogged or gummed up with dirt.
One problem with touchpads is that they require a wider range of finger motion to operate than a track ball. A track ball requires a minimal amount of finger movement, approximately a 1/4 of an inch circle around the device. With a touchpad however, the user is required to incorporate the full width and length of the pad, approximately 11/2 to 2 inches, to move the cursor. With a flat touch pad, this increased area of coverage by the finger may require movement of the entire hand and arm to operate the touchpad. The increase in arm movement of the computer causes a slower response time and a definite break in the typing rhythm.
Although touchpads are usually flat or planar, touchpads can also be non-planar as well. An outwardly non-planar operating surface advantageously provides the computer system with an input device that protrudes outward away from the base portion, thereby minimizing the area on the top surface of the base portion needed for the touch pad. Also, the outwardly non-planar surface advantageously provides a cursor moving and input device with better ergonomics where the user has a smaller area to traverse the entire pad.
Another advantage of this outwardly non-planar operating surface is that it provides the user with a partially vertical operating surface. This partially vertically surface enables the user to move the cursor with a partial vertical motion of a finger instead of with only a horizontal motion as with a non-planar surface. This partially vertical motion for cursor control provides for better ergonomics. In addition, a protruding operating surface enables the cursor to be controlled with a partially vertical motion from a side of the touch pad where such a motion is easier to make while typing than a purely horizontal motion with a flat operating surface. Thus, there is less hand movement required to contact the operating pad.
Inwardly non-planar touchpads also provide advantages not available with planar touch pads. Because the human figure rotates on a joint, the natural movement of the figure is in an inward arching motion. Thus, a touchpad with an operating surface that follows this motion would require less hand movement in controlling a cursor.
Because different users have different typing styles, a touchpad operating surface ideal for one user may slow down the typing speed of another user.
Another way to advantageously make a touchpad adjustable is to allow a user to orient the touchpad in variety of ways with respect to the computer system. Because touchpads are not symmetrically global, certain orientations of the touchpad are more convenient for users with different typing styles. It is known that a computer system is able to detect an orientation of a touchpad in a computer system and adjust the cursor control movements according to the orientation. Clark et al., U.S. Pat. No. 5,469,194, teaches one method of compensating for a physical orientation of a touch pad relative to the display screen. This method allows for a horizontal movement on the touch pad operating surface to cause a horizontal movement of the cursor independent of which orientation is used.
What is needed is an input device that will improve the ergonomics of using the touchpad by allowing each individual user the ability to adjust the operating surface of the touchpad to a number of various operating positions by changing the form of the operating surface or by changing the orientation of the operating surface. What is also needed is a touchpad that can be adjusted by a user to fit the specific needs of the user in operating a computer. What is further desired is a touchpad that allows the user to adjust the form or orientation of the operating surface in a convenient, and inexpensive way, and without the use of tools.